"We are well advanced with the sale process, however due to regulatory constraints and the confidentiality of the process, we will not be commenting on any individual bidders or elements of the transaction process until its completion," he said in an e-mail to Dow Jones Newswires.

The sale of some Asian assets is part of the group's plan to exit non-core businesses in select markets to raise capital.

The assets, which are in India, Taiwan, Indonesia and elsewhere, are a portion of the Asian assets acquired by RBS when it led a consortium to buy part of ABN Amro Holding NV in 2007.

The other consortium partners included Fortis Group of the UK and Banco Santander SA of Spain.

In India, RBS has 31 bank branches and about 10,000 employees.

On Monday, Mint newspaper reported that the Indian central bank blocked RBS from transferring its bank licenses to prospective buyers.

The Reserve Bank of India decided that the transaction was a portfolio sale and not a bank acquisition, the report said.

An RBS official, who didn't wish to be named, said the bank always knew bank licenses in India "cannot be bought and sold."

"I'm sure even the prospective buyers are aware when they are doing their due diligence," he said.